Circuit breaker



June 1, 1943. E, T. PLATZ 2,320,382

CIRCUIT BREAKER Filed Oct. 4, 1941 3 Sheets- Sheet 2 I jlO R w I ATTORNEY.

June 1, 1943. E. T. PLATZ cmcun BREAKER Filed Oct. 4, 1941 s Sheets-Sheet3 INVENTOR. T F 41; 4/? L ATTORNEY M m M 0 W mfifw H M w 1 J M m M m 7 M w We 5 W Patented June 1, 1943 CIRCUIT BREAKER Elwood T. Platz, Detroit, Mich, assignor to Bulldog Electric Products Company, Detroit, Mich., a corporation of West Virginia Application October 4, 1941, Serial No. 413,673

18 Claims.

This application discloses a novel form of circuit breaker for an understanding of which reference should be had to the appended drawings.

In these rawin Fig. l is a cut-away view, on line l--l, Fig. 6, showing the parts in the closed circuit position.

Fig. 2 is a plan view on line 2-2, Fig. 1.

Fig. 3 shows the parts in the open circuit position.

Fig. 4 shows the parts in the overload released position.

Fig. 5 is a fragmentary view of an indexing over-center means, on line 5--5, Fig. 6.

Fig. 6 is a plan view.

Figs. 7 and 8 are fragmentary views.

The circuit breaker hereof comprises a casing I0 having top and bottom cover plates II and I2. Projecting through a slot of the top cover plate is a manually removable support or handle l3 having a journal shaft l4 providing an axis of rotation. The handle is of the rocker, push-only, type and is U shaped so as to have legs l5, I6 within which, and supported by which, is the movable mechanism of the breaker.

The mechanism includes a contact frame having three relatively movable contacts I! slidably mounted in triangularly arranged slots l 8 of legs l5, l6. Portions of slots l8 of leg IE only are covered by a disc I9 which seats a trip spring 20 acting on an insulating disc 2| engaging the contacts l l and forming with them a contact frame.

The three movable contacts I! control the three poles controlled by the breaker.

Latches, in the form of bi-metal strips 22 integrally fastened to and forming part of the contacts l1, releasably latch the contacts to an insulation disk 24, at three points thereof, with the latch points being triangularly spaced about a center pin 25 mounting the disc on handle I 3 in a manner to permit the disc to tilt freely on the end of center pin 25. Large holes 26 in disc 24 permit the contacts I! to pass clear through them. Thus, disc 24, a part of handle i3, is a support for the frame, whose supporting legs are bi-metal strips 22.

For resetting the tilted disc 24 on pivot pin 25, to the ends of the bi-metal strips 22, there are provided books 21 hooking freely around the edge of the disc 24.

Flexible conductors 28 connect the bi-metal strips at their free ends to one set of terminal binding posts and the circuit is completed by the provision of contact tips 30 On the contacts ll which engage contact tips 3i of straps connected to other terminal binding posts 32.

The switching points 30-3l of the various poles are isolated relatively by barriers 33 formed wlthin the casing l0. A sloping wall34, also formed as part of the casing, provides a stop for limitin counterclockwise movement of the support or handle lLand the mechanism within and carried by it.

An indexing snap spring arrangement for the handle l3, which includes an arm 35 fastened to shaft l4 and acted upon by an over-center snap action spring 36 is disposed in a supplementary compartment 31 of casing l0. Spring 36 biases the handle and the mechanism carried thereby into the circuit closed position for establishing contact pressure, and also biases them into the circuit open position to hold them at rest, and also provides accelerated snap movement at the end of each switching stroke of the handle.

Contacts ll, as shown, are relatively movable. By tilting as necessary, disc 24 forms a resilient "floor for the three legs ll of the frame, tilting in order to equalize contact pressure of the contacts l! on the stationary contacts, with that pressure being provided by the handle indexing spring 36.

Latches 22, as shown, are relatively slidable (with contacts ll). Thus disc 2i equalizes the latching pressure of spring 20 on latches 22 on disc 24.

The operation of the breaker will now be described:

Manual switching is accomplished simply by rocking of the handle on its pivotal axis, the entire mechanism within it moving with the handle, though not relatively to it.

On the arising of an overload in any one pole the bi-metal strip or latch 22 thereof will move outwardly from the disc 24 to release one point of that disc; thereupon the spring 20 will slide the contact frame from the closed circuit position, the disc tilting so as not to interfere with such sliding motion of the frame. The parts will come to rest in circuit open position with the disc tilted and out of engagement with one or more of the ends of the bi-metal strips.

For relatching the released bi-metal strips and the disc, the handle is rocked towards the open circuit position so that those ends of the contacts which had been caused to slide towards wall 34 by the spring 20 on latch release, will engage wall 34 and thereafter remain stationary. During further rocking of the handle towards open circuit position, hooks 21 of the frame will cause disc 24, a part of the handle, to tilt on pin 25 in thereverse direction, opposite its releasing direction, until it moves behind the ends of the bi-metal strips 22 which had released it and will thus re-engage such ends.

If all three bi-metals warp simultaneously, the frame will be released to move, without tilting of the disc; and in relatching, no reverse tilting of the disc will be required.

An understanding of the release action of the breaker may be obtained from viewing the parts by analogy to a three legged stool. If one of the legs of a three legged stool is pulled out laterally, so as not to engage the floor, then a force on the stool will cause it to fall. In the instant breaker there is a frame comprising three bimetal strips 22 and their contacts [1; and this is supported at three points, the ends of the bi-metal strips, on the disc 24. On latch release at any one point of the disc, the support for the frame will be removed and the load or spring force will cause the frame to move from the stationary contacts.

Now having described the circuit breaker herein disclosed, reference should be had to the claims which follow for a determination of the invention.

I claim:

1. In a circuit breaker, an automatically rcleasing manually resettable mechanism in the form of a center mounted disc and a contact frame comprising three overload releasable latches, each latching to said disc, the three latching points being triangularly arranged around the center mounting of the disc, and spring means for causing said contact frame to shift for circuit opening and said disc to rock on its center mounting upon the release of the latch engagement between said disc and any one of said latches.

2. In a circuit breaker, an automatically releasing manually resettable mechanism in the form of a center mounted disc and a contact frame comprising three overload releasable latches, each latching to said disc, the three latching points being triangularly arranged around the center mounting of the disc, and spring means for causing said contact frame to shift for circuit opening and said disc to rock on its center mounting upon the release of the latch engagement between said disc and any one of said latches, each latch comprising a bi-metal strip forming part of thecontact frame, with its free end engaging the disc.

3. In a circuit breaker, an automatically releasing manually resettable mechanism in the form of a center mounted disc and a contact frame comprising three overload releasable latches, each latching to said disc, the three latching points being triangularly arranged around the center mounting of the disc and spring means for causing said contact frame to shift for circuit opening and said disc to rock on its center mounting upon the release of the latch engagement between said disc and any one of said latches, and a manually actuable spring snapped means for shifting said mechanism as a, unit bodily, for manual switching operation, without relative movement of the disc, the spring, or the frame.

4. In a circuit breaker, an automatically releasing manually resettable mechanism in the form of a center mounted disc and a contact frame comprising three overload releasable latches, each latching to said disc, the three latching points being triangularly arranged .around the center mounting of the disc, and

spring means for causing said contact frame to shift for circuit opening and said disc to rock on its center mounting upon the release of the latch engagement between said disc and any one of said latches, and a manually actuable spring snapped means for shifting said mechanism as a unit bodily, for manual switching operation, without relative movement of the disc, the spring, or the frame, the mechanism, as a unit, remaining stationary with respect to the manually actuable means during overload release movement of the parts of the mechanism with respect to one another so that overload release or circuit opening movement may be free of the handle.

5. In a circuit breaker, a manually movable U shaped handle, an automatically releasing manu ally resettable unitary mechanism therein comprising a frame within and slidably mounted at an end in one leg of the U of the handle, a disc center mounted on the opposite leg and disposed within said handle, said frame having three overload releasable latches latching said frame to said disc at points arranged triangulafiy about "its center mounting and peripherally spaced from one another, and spring mean reacting on the handle for causing said frame to slide for circuit opening and'said disc to rock on its, center mounting upon the release of any of the three latch engagements between said disc and said frame, the handle remaining stationary during such movement.

6. In a circuit breaker, a manually movable U shaped handle, an automatically releasing manu-.

ally resettable unitary mechanism therein comprising a frame within and slidably mounted at an end in one leg of the U of the handle, a disc center mounted on the opposite leg and disposed within said handle, said frame having three overload releasable latches latching said frame to said disc at points arranged 'triangularly about its center mounting and peripherally spaced from one another, and spring means reacting on the handle for causing said frame to slide for circuit opening and said disc to rock on its center mounting upon the release of any of th three latch engagements between said disc and said frame, the handle remainig stationary during such movement,'the handle being manually actuable and also spring snapped for shifting itself and the mechanism therein as a unit bodily, for manual switching operation.

7. In a circuit breaker, a manually movable U shaped handle, an automatically releasing manually resettable unitary mechanism therein comprising a frame within and slidably' mounted at an end in one leg of the U of the handlev a disc center mounted on the opposite leg and disposed within said handle, said frame having three overload releasable latches latching said frame to said disc at points arranged triangularly bout its center mounting and peripherally spaced from one another, and spring means reacting on the handle for causing said frame to slide for circuit opening and said disc to rock on its center mounting upon the release of any of the three latch engagements between said disc and said frame, the handle remaining stationary during such movement, the handle being manually actuable and also spring snapped for shifting itself and the mechanism therein as a unit bodily, for manual switching operation, the mechanism, as a unit, remaining stationary with respect to the handle during overload release movement of the parts of the mechanism with respect to one another so that overload release or circuit opening movement may be free of the handle.

8. In a circuit breaker, a manual actuatona movable contact frame movably mounted thereon at one location and releasably interlatched thereto at another, spring means biasing the frame to open circuit position on latch release, and means interlatching the actuator and frame comprising a plate fixed to the actuator, three circuit responsive latches of the frame arranged triangularly and releasably holding the plate, with each latch responsive to the condition of a pole of the circuit for moving and thus releasing its hold on the plate, the spring causing circuit opening move ment of the frame relative to the actuator, on release movement of any latch, with respect to the plate.

9. A circuit breaker having a contact frame, a support providing three separate support points therefor on all three of which the frame must rest to be maintained in circuit closing position, means responsive to the condition of a pole for moving and thus releasing the contact frame relative to the support on the arising of a circuit abnormality in any pole, the support points being arranged triangularly whereby if at any one point there is a release of the contact frame, the latter is unsupported, and is free to move to open circuit position.

10. A circuit breaker having a contact frame, a support providing three separate support points therefor on all three of which the frame must rest to be maintained in circuit closing position, means responsive to the condition of a pole for moving and thus releasing the contact frame relative to the support on the arising of a circuit abnormality in any pole, the support points being arranged triangularly whereby if at any one point there is a release of the contact frame, the latter is unsupported, and is free to move to open circuit position, the support and frame being manually movable as a unit, without relative movement, so as to move the frame to and from open circuit position.

11. A circuit breaker having a contact frame, a support providing three separate support points therefor on all three of which the frame must rest to be maintained in circuit closing position, means responsive to the condition of a pole for moving and thus releasing the contact frame relative to the support on the arising of a circuit abnormality in any pole, the support points being arranged triangularly whereby if at any one point there is a release of the contact frame, the latter is unsupported, and is free to move to open circuit position, the support and frame being manually movable as a unit, without relative movement, so as to move the frame to and from open circuit position, and manually actuable means for moving the support and frame relatively, after the support had moved relative to the frame to release it, for reestablishing an unreleased or supporting connection between the support and the frame.

12. A circuit breaker having a support, a contact frame supported thereby at three support points, triangularly arranged so that all three points of the frame must be in supporting engagement with the support in order for the frame to be in circuit closed position, circuit responsive means for each support point for releasing the support point controlled by iton the arising of a predetermined circuit condition in the pole controlling it, whereby the frame will be freed from the support to move to open circuit position, on the arising of that predetermined circuit condition in any pole.

- 13. A circuit breaker having a support, a contact frame supported thereby at three support points, triangularly arranged so that all three points of the frame must be in supporting engagement with the support in order for the frame to be in circuit closed position, circuit responsive means for each support point for releasing the support point controlled by it on the arising of a predetermined circuit condition in the pole controlling it, whereby the frame will be freed from the support to move to open circuit position, on the arising of that predetermined circuit condition in any pole, the support and frame being movable manually as a unit, without relative movement, for switching action.

14. A circuit breaker having a support, a contact frame supported thereby at three support points, triangularly arranged so that all three points of the framemust be in supporting engagement with the support in order for the frame to be in circuit closed position, circuit responsive means for each support point for releasing the support point controlled by it on the arising of a predetermined circuit condition in the pole con trolling it, whereby the frame will be freed from the support to move to open circuit position, on the arising of that predetermined circuit condition in any pole, the support and frame being movable manually as a unit, without relative movement, for switching action, and manually actuable means for moving the support and frame relatively, after the support had moved relative to the frame to release it, for reestablishing an unreleased or supporting connection tween the support and the frame.

15. In a circuit breaker, three movable contacts, a center mounted tiltable support therefor engaged by the contacts at three points defining a plane, a spring biasing the support, and thus biasing the contacts against stationary contacts for contact pressure, with the support tilting as necessary on its center mounting to equalize contact pressure.

16. In a circuit breaker, three movable latches, a support releasably engaged thereby, a spring biasing the latches against said support for latching pressure, and a latch pressure equalizer plate engaged by the latches at three points defining a plane and engaged by the spring for distributing the latching pressure of the spring on the latches in a manner to equalize the en" gagement pressure of the latches on the support.

17. In a circuit breaker, an actuator, an indeizing spring therefor acting thereon and reacting on a stationary part of the breaker, three'rnov able contacts, a support therefor tiltably mounted at its center on the actuator and releasably engaged by the contacts at three points defining a plane, the spring biasing the actuator and the support carried by it, and thus biasing the contacts against stationary contacts for contact pressure, with the support tilting as necessary on its center mounting to equalize contact pressure.

18. In a circuit breaker, an actuator, an indexing spring therefor acting thereon and reacting on a stationary part of the breaker, three movable contacts, a support therefor tiltably mounted at its center on the actuator and releasably engaged by the contacts at three points defining a plane, the spring biasing the actuator and the support carried by it, and thus biasing the contacts against stationary contacts for contact pressure, with the support tilting as necessary on its center mounting to equalize contact pressure, a spring reacting on the actuator for biasing the contacts against said support to maintaii" them engaged, and a pressure equalizer plate engaged by the contacts at three points defining a plane and engaged by the latter spring for distributing its pressure on the contacts in a manner to equalize the engagement pressure of the contacts on the support.

ELWOOD PLATE. 

